Mechanical stoker



1. e. MIDGLEY.

- MECHANICAL STOKER.

APPLIGATION. HLED JAN. 2,1918.

Pawn June 1, 1920.

2 SHEETSSHEET 1.

nuantoz UNITED STATES PATENT OFFICE.-

J'OHN G. MIDGLEY, 0F SALT LAKE CITY, UTAH.

MECHANICAL STQ KER.

Specification of Letters Patent.

Patented June 1, 1920.

To all whom it may concern.-

Be it known that 1, JOHN G. MIDGLEY, a citizen of the United States, residing at Salt Lake City, in the county of Salt Lake and State of Utah, have invented certain new and useful Improvements in Mechanical Stokers, of which the following is a spec1- fication.

This invention relates to mechanical stokers and more particularly to stokers of the Jones, American, Moloch, etc., type, wherein the coal is forced into a longitudinally extending, open top retort disposed. within the furnace and thence distributed over the combustion surfaces. I One of the primary objects of my invention is to provide an improved stoker of thegeneral type aforesaid wherein a more efficient combustion is attained, efl'ectlve operation is facilitated, burning out of the parts is avoided, replacement and repair 1s rendered easy, elimination of clinker and other waste is facilitated and the otherwise waste heat of the discharged ash and highly heated clinker is utilized to initially heat the air by which the green coal is brought to a state of incandescence at the'time that it begins its passage over the combustion surfaces.

Further objects and advantages of the invention will be set forth in the detailed de-- scription which now follows:

In the accompanying drawings;

Figure 1 is an end view partly in front elevation and partly in transverse section of a furnace and stoker constructed in accordance with the invention and Fig. 2 is a longitudinal vertical section through one of the dumping plates looking toward one of the combustion plates.

Like numerals designate corresponding parts in all of the figures of the drawings.

In furnaces of the general type referred to it is common to provide a hopper 5 for the coal from which hopper the coal. is delivered to and distributed longitudinally in conveyer, or any other well known type of conveyer.

At its upper edges the retort 6 is provided with outstanding flanges 8, having upturned lips 9, it being understood that the structure shown at the right hand side of Fig. 1, is duplicated at the left side of the center thereof. The flanges 8 are provided with longitudinally extending tapering openings 10 which serve as seats for downward exten- 810118 11 of the twyer blocks 12. These blocks have openings 13 of considerable area formed therein, which openings face toward the retort 6 and these blocks also have openings 14 formed therein which extend substantially horizontally through the outer side walls 15 of the blocks. Angle plates 16 are fixed within the furnace and extend longitudinally therethrough and these plates in conjunction with the flanges 8, serve to support inclined combustion plates 17 said plates having downturned lips 18 which bear against the angleplates 16 and downturned arms 19 which hook over lips 9 and rest upon the flanges 8. An advantageous feature of this construction is that it permits of ready removal of the combustion plates 17. The upper faces of the combustion plates are stepped at -20 and the mouths 21 of orifices 22 open at these stepped portions. Sheet iron division walls 23 extend from the angle plates 16 to the bottom of the structure and divide the space beneath the combustion plates and twyer blocks into ash and clinker pits 24 and an air plenum 25. Airmay be applied to the air plenum 25 in any desired manner. As illustrating one way in which it may be supplied I have indicated air supply pipe 26. Air tight cover plates 27 are adapted to close openings 28 in the division walls 23 to permit the passage of a person into the air plenum from the pits 24. Dumping plates 29 are mounted upon rock shafts 30 which shafts are journaled in the end walls of the furnace indicated at 31 and 32. These shafts have angular ends 33 disposed outwardly of the furnace to permit of the manual actuation of the dumping plates by the application of a suitable tool, not shown, thereto. Plates 34 are secured to the angle plates 16 and close the space at the rear or hub sides of the dumping plates 29. Doors 35 permit access to the combustion chamber 36 of the furnace above the combustion plates-17 and dumping plates 29, and doors 37' permit access to the interior of the pits 24.

It is to be noted that the twyer blocks 12 are provided with inclined upper faces 12 which conform in general inclination to the inclination of the combustion plates 17. The result is that there is a gradual feeding action of the coal over these inclined faces of the blocks and over the inclined faces of the combustion plates 17. It is further to be noted that the openings 13 exceed in area the openings 14 and that consequently the major portion of the-air"from the blocks 12 v will pass into the upper outer edge of thebody of green coal which, coupled with the fact that the air thus supplied is in a highly heated condition due to its contact" with the sheet metal walls 23 of the pits 24, the combustion plates 17 and the under sides of the flanges 8 and the twyer blocks, results in bringing the mass of the coal to a state of incandescence before it passes upon the combustion plates 17.

The provision of the doors 34 renders it possible for the fireman to have access to the combustion chamber 36 to clean the fire or otherwise manipulate the same to secure the most efiicient results, while the provision of the dumping plates 29 permits the ash and clinkers to be dumped into the pits 24 without the necessity of opening the doors 37 if this be desired. It is further to be noted that the otherwise waste heat of the incandescent clinkers dum ed into pits 24 isutilized to highly heat t e air in the air plenum 25 before it passes into the twyer blocks and thence to-the coal, it being understood that the air in the air plenum is preferably maintained under pressure,,approximately two ounces being found to be about the right pressure to secure the desired results. During its passage overthecombustion plates the coal is'subjected to further injections of highly heated air from mouths 21 of openings 22 and the combined result is that a highly economical and efficient result is produced, I

While the elements shown and described vare well: adapted to serve the purposes for 4 ap ended claims.

- open top retort, of'means for feeding coa aving described my invention what I claim is; V

1. In a furnace construction the combination with a longitudinally extendin thereinto, a plurality of twyer ocks ,mounted along each upper edge of the re-- tort, which blocks are hollow, are open at the space beneath the combustion plates into an air plenum and ash pits, dumping plates dis osed outwardly of the combustion plates an" discharging into the ash pits, the said air plenum having direct communication with the interiors of the twyer blocks through the open bottoms thereof and also having direct communication with the ports of the combustion plates, and means for supplying air under pressure to the air plenum.

2. In a furnace construction, the 'combina-' tion with a longitudinally extending open top retort of means for feeding coal thereinto, inclined combustion plates, the space above which constitutes the combustion chamber, twyer blocks disposed at the upper edges of the retort and having ports directed outwardly from the twyer blocks over the inclined plates, said plates having additional ports leading therethrough from the bottom to the top thereof at intervals from the twyer blocks outwardly, division walls dividing the space beneath each combustion plate and retort into ash pits and an air plenum, said division walls comprising a vertical portion and a substantially horizontal portion the latter extending a material distance outwardly beyond the vertical portion to thereby cause the ash pit space to project beneath the combustion plates while leaving the ports formed through the combustion plates in communication with the air plenum and means for supplying air under pressure to the air plenum, the interior of the twyer blocks being in communication with the air plenum.

3. In a furnace construction, the combination with a retort, of twyer blocks outwardly thereof, dumping plates disposed ad'acent the outer side of the furnace and fixe forated combustion plates disposed inclinatorially between the twyer blocks and the dumping plates, and the space beneath the twyer blocks retort and the combustion plates and the dumping plates being divided by longitudinall disposed division walls into ash pits an an air plenum, means for supplying air under pressure to the air plenum, the latter extending entirely between division walls so that all of the air that enters said air plenum and that passes through the twyer blocks and the combustion plates is heated by contact with said perdivision walls the said air plenum and ash pits lying "substantially in the same horizontal plane so that all of the heat in the ashes is utilized in heating the air in the air plenum.

4. A structure as recited in claim 3 wherecause the greater portion of the air which enters the air plenum to be discharged throu 'h the twyer blocks. 5.

structure as recited in claim 3 wherein the twyer blocks are provided-with openings disposed toward the retortsaid openmgs being greater in area than the openings formed through the inclined combustion plates whereby the greater part of the air delivered to the air plenum is caused to pass through the twyer blocks and to be discharged toward the body of coal in the retort.

6. A structure as recited in claim 3 wherein the ash pits are provided with a closure to retain the heat from the precipitated ash and to impart the same to the air in the air plenum;

- 7. A structure as recited in claim 3 wherein the retort is provided with an open top, and means for forcing coal into said retort, the coal overflowing the top of the retort and traveling by gravity over the inclined combustion plates to the dumping plates.

8. A structure as recited in claim 3 wherein the air openings through the inclined combustion plates are disposed in such direction that the blast of air therefrom tends to cause the coal to move downwardly over said combustion plates assisted by gravity.

9. A structure as recited in claim 3 wherein the retort is provided with an open top and means for forcing coal thereinto, said twyer blocks having inclined upper faces which conform tothe inclination of the combustion plates, the coal overflowing from the retort traveling over the inclined faces of the twyer blocks and over the inclined combustion plates to the dumping plates.

10. A structure as recited in claim 3 wherein the upper faces of the combustion plates are stepped and wherein the openings through said combustion plates open at stepped portions thereof, the retort being open at the top and the coal therefrom traveling over the combustion plates by gravity assisted by. the action of the air discharged at the stepped portions of the combustion plates.

11. 'A structure as recited in claim 3 in which. doors are provided in the division JOHN G. MIDGLEY.

Witnesses:

DANL HARRINGTON, H. W. HARTLEY. 

